US3284513A - Process for the thermal hydro-dealkylation of cresols - Google Patents
Process for the thermal hydro-dealkylation of cresols Download PDFInfo
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- US3284513A US3284513A US245848A US24584862A US3284513A US 3284513 A US3284513 A US 3284513A US 245848 A US245848 A US 245848A US 24584862 A US24584862 A US 24584862A US 3284513 A US3284513 A US 3284513A
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- phenol
- cresol
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- benzene
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- 238000000034 method Methods 0.000 title claims description 15
- 150000001896 cresols Chemical class 0.000 title description 4
- 238000006900 dealkylation reaction Methods 0.000 title description 3
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 47
- 238000006243 chemical reaction Methods 0.000 claims description 27
- 239000001257 hydrogen Substances 0.000 claims description 27
- 229910052739 hydrogen Inorganic materials 0.000 claims description 27
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 claims description 20
- 229930003836 cresol Natural products 0.000 claims description 20
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical class [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 19
- 239000007795 chemical reaction product Substances 0.000 claims description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 48
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 41
- 150000002989 phenols Chemical class 0.000 description 16
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 150000002431 hydrogen Chemical class 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 6
- 150000001555 benzenes Chemical class 0.000 description 6
- QWVGKYWNOKOFNN-UHFFFAOYSA-N o-cresol Chemical compound CC1=CC=CC=C1O QWVGKYWNOKOFNN-UHFFFAOYSA-N 0.000 description 6
- 229920006395 saturated elastomer Polymers 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 125000000217 alkyl group Chemical group 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 125000003118 aryl group Chemical group 0.000 description 3
- -1 cresols Chemical class 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- IWDCLRJOBJJRNH-UHFFFAOYSA-N p-cresol Chemical compound CC1=CC=C(O)C=C1 IWDCLRJOBJJRNH-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000000571 coke Substances 0.000 description 2
- 230000020335 dealkylation Effects 0.000 description 2
- 238000004508 fractional distillation Methods 0.000 description 2
- RLSSMJSEOOYNOY-UHFFFAOYSA-N m-cresol Chemical compound CC1=CC=CC(O)=C1 RLSSMJSEOOYNOY-UHFFFAOYSA-N 0.000 description 2
- 229940100630 metacresol Drugs 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- NUMXHEUHHRTBQT-AATRIKPKSA-N 2,4-dimethoxy-1-[(e)-2-nitroethenyl]benzene Chemical compound COC1=CC=C(\C=C\[N+]([O-])=O)C(OC)=C1 NUMXHEUHHRTBQT-AATRIKPKSA-N 0.000 description 1
- PHVAHRJIUQBTHJ-UHFFFAOYSA-N 3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1 PHVAHRJIUQBTHJ-UHFFFAOYSA-N 0.000 description 1
- 229910000809 Alumel Inorganic materials 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 241000404158 Lonas Species 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 150000002931 p-cresols Chemical class 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 125000003944 tolyl group Chemical group 0.000 description 1
Images
Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/50—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions decreasing the number of carbon atoms
Definitions
- This invention relates to a process for the thermal hydrodealkylation of a monoalkylated phenol, such as cresols, to obtain phenol.
- Alkyl aromatics such as toluene
- the alkyl group is cleaved from the alkyl aromatic and combines with the hydrogen present to form a saturated aliphatic hydrocarbon.
- the desired aromatic can be separated from the saturated aliphatic hydrocarbon and unreacted alkyl aromatic, if present, in any convenient manner.
- a monoalkylated phenol such as a cresol
- maximum selectivity to phenol can be obtained by converting no more than about 88 to about 92 mol percent, preferably no more than about 90 mol percent, of the monoalkylated phenol subjected to thermal hydrodealkylation. Any amount of monoalkylated phenol below the defined amount can be converted and maximum selectivity to phenol will result when the monoalkylated phenol is heated at the elevated temperatures defined herein in the presence of hydrogen, but for economic purposes we prefer to convert on a minimum basis about 25 to about 35 mol percent of the monoalkylated phenol charge.
- the reaction product obtained at the end of the conversion period will contain predominantly monoalkylated benzene such as toluene, phenol, benzene, methane, water and unreacted monoalkylated phenol and hydrogen.
- An embodiment of our invention envisions separating phenol, benzene, methane, Water and unreacted monoalkylated phenol and hydrogen from the reaction product.
- Monoalkylated benzene, such as toluene, remaining can then be subjected to thermal hydrodealkylation as set I forth hereinabove to obtain additional benzene.
- the charge for example, cresol (ortho, meta or para or any combination thereof) and hydrogen, together'or separately, are first preheated to reaction temperature in any suitable manner, for example by passing the same through a tubular member in indirect contact with heat-producing elements such as burners.
- the amount of hydrogen which must be present in the charge must be that sufiicient to replace the alkyl chain and hydroxyl group cleaved from the aromatic ring at the elevated reaction temperature and also to combine with the alkyl chain and hydroxyl group so removed to form a saturated aliphatic hydrocarbon and water, respectively.
- the molar ratio of hydrogen to monoalkylated phenol can vary over a wide range a molar ratio of one to about 10, preferably about four to about eight, is employed.
- reactor any type of reactor, but preferably a tubular reactor, heated, for example, in the same manner as the preheater described above, can be employed.
- the walls of the reactor should be free of material which will catalyze the thermal dealkylation procedure defined herein, and the interior of the reactor should similarly be free of catalytic material.
- the reactor can be filled with noncatalytic material, such as quartz chips, in order to effect better mixing and to reduce temperature gradients therein.
- the temperature required to etfect the desired hydropressure is not critical and can be in excess of about pounds per square inch gauge, we prefer to employ apressure in the range of about 200 to about 1000 pounds per square inch gauge.
- reaction is continued and then terminated, as noted hereinabove, when no more than about 88 to 92 mol percent of the monoalkylated phenol has been converted.
- reaction mixture is quenched to a temperature where the reaction essentially ceases, which can be from about 80 to about 800 F., in any suitable manner, for example, by direct contact with cooled, previously-formed product.
- the product obtained consists essentially of phenol, monoalkylated benzene, such as toluene, benzene, unreacted monoalkylated phenol and hydrogen, methane, water and some heavy material believed to be conjugated phenol, toluene and benzene derivatives.
- this product can be treated in any suitable manner to re move water therefrom, for example, by passing the same through 4A Linde molecular sieves or other adsorbent material having a greater specificity for water than the hydrocarbons or phenol.
- the remaining product for purposes of recovery can be separated into its individual components or selected combinations thereof by any suitable means, by fractional distillation at subatmospheric, atmospheric or superatmospheric pressure, for example, a temperature of about to about 450 F. and atmospheric pressure.
- a fraction thereof containing solely a monoalkylated benzene, such as toluene, or in combination with benzene, together with about one to about 10 mols thereof of hydrogen can be subjected in the same reactor, or one similar to the reactor employed to convert monoalkylated phenol to phenol, to a temperature of about 1050 to about 1350 F. and a pressure of about 250 to about 1200 pounds per square inch gauge while employing a space velocity of about 0.5
- the monoalkylated ben- A space velocity of at least about zene, such as toluene, will be converted to benzene and methane will be obtained in the manner previously described.
- the product can be quenched to a temperature where the reaction essentially ceases, which can be in the range of about 80 to about 800 F., in any suitable manner, and the benzene recovered therefrom by fractional distillation at subatmospheric, atmospheric or superatmospheric pressures, for example, at 240 F. and atmospheric pressure.
- Thermal hydrodealkylation runs were made, using as charge therefor ortho, metaand p-cresols, in a reactor having a length of four inches and an inner diameter of one inch filled with a noncatalytic material, quartz chips, to elfect better mixing and to reduce temperature gradients.
- Each of the charge stocks was mixed with hydrogen before preheating.
- the average reactor temperature was determined from several temperature measurements made inside the reactor with a movable chromel-alumel thermocouple. Pressures and temperatures were maintained at set values by means of automatic control instruments. The unit was run two hours offstream to allow for stabilization of process conditions.
- the hydrogen employed in the thermal hydrodealkylation process defined herein need not be pure but may be present in a gaseous stream also containing materials which will not adversely affect the desired reaction.
- Coke oven gas for example, can advantageously be employed for purposes of supplying hydrogen for the reaction.
- the composition of coke oven gas, in mol percent, is as follows: 53.1 percent hydrogen, 26.2 percent methane, 5.3 percent ethane and ethylene, 0.4 percent heavier hydrocarbons, 5.8 percent carbon monoxide, 2.8 percent carbon dioxide, 0.5 percent hydrogen sulphide and 5.9 percent nitrogen.
- the resultant gas will contain more saturated aliphatic hydrocarbon and less hydrogen than the charge gas. Since on a volume basis the saturated aliphatic hydrocarbon has a higher caloric value than hydrogen, the result-ant gas will have an enhanced caloric value. For such reason in some cases an impure hydrogen stream is desirable as a source of hydrogen.
- a process for converting a cresol which comprises Run N0 1 2 3 4 5 6 7 8 9 10 11 Charge.
- a process for converting ortho cresol which comprises reacting ortho cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction prodnot.
- a process for converting meta cresol which comprises reacting rneta cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction product.
- a process for converting para cresol which comprises reacting para cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction product.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
United States Patent 3,284,513 PROCESS FOR THE THERMAL HYDRO- DEALKYLATION 0F CRESOLS .lonas Dedinas, Pittsburgh, Alfred M. Heuke, Springdale,
and William C. Oifutt, Pittsburgh, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a
corporation of Delaware Filed Dec. 19, 1962, Ser. No. 245,848 4 Claims. '(Cl. 260621) This invention relates to a process for the thermal hydrodealkylation of a monoalkylated phenol, such as cresols, to obtain phenol.
Alkyl aromatics, such as toluene, can be dealkylated to lighter aromatics, such as benzene, by subjecting such alkyl aromatic in the presence of hydrogen but in the absence of catalyst to an elevated temperature and an elevated pressure for a controlled length of time. As a result of such reaction conditions the alkyl group is cleaved from the alkyl aromatic and combines with the hydrogen present to form a saturated aliphatic hydrocarbon. The desired aromatic can be separated from the saturated aliphatic hydrocarbon and unreacted alkyl aromatic, if present, in any convenient manner.
When a monoalkylated phenol, such as a cresol, is
similarly subjected to thermal hydrodealkylation, not only is the alkyl substituent removed and the same results noted above obtained, but there is also a tendency for the hydroxyl group to be cleaved from the aromatic ring and be replaced with a hydrogen. The hydroxyl group so removed combines with another hydrogen to form water. Accordingly a monoalkylated phenol, under such circumstances, will be converted to benzene instead of phenol and a large amount of methane and Water will be formed.
We have found that a monoalkylated phenol, such as a cresol, can be dealkylated and maximum selectivity to phenol can be obtained by converting no more than about 88 to about 92 mol percent, preferably no more than about 90 mol percent, of the monoalkylated phenol subjected to thermal hydrodealkylation. Any amount of monoalkylated phenol below the defined amount can be converted and maximum selectivity to phenol will result when the monoalkylated phenol is heated at the elevated temperatures defined herein in the presence of hydrogen, but for economic purposes we prefer to convert on a minimum basis about 25 to about 35 mol percent of the monoalkylated phenol charge.
The reaction product obtained at the end of the conversion period will contain predominantly monoalkylated benzene such as toluene, phenol, benzene, methane, water and unreacted monoalkylated phenol and hydrogen. An embodiment of our invention envisions separating phenol, benzene, methane, Water and unreacted monoalkylated phenol and hydrogen from the reaction product. Monoalkylated benzene, such as toluene, remaining can then be subjected to thermal hydrodealkylation as set I forth hereinabove to obtain additional benzene.
In order to carry out the reaction the charge, for example, cresol (ortho, meta or para or any combination thereof) and hydrogen, together'or separately, are first preheated to reaction temperature in any suitable manner, for example by passing the same through a tubular member in indirect contact with heat-producing elements such as burners. The amount of hydrogen which must be present in the charge must be that sufiicient to replace the alkyl chain and hydroxyl group cleaved from the aromatic ring at the elevated reaction temperature and also to combine with the alkyl chain and hydroxyl group so removed to form a saturated aliphatic hydrocarbon and water, respectively. In general while the molar ratio of hydrogen to monoalkylated phenol can vary over a wide range a molar ratio of one to about 10, preferably about four to about eight, is employed.
Any type of reactor, but preferably a tubular reactor, heated, for example, in the same manner as the preheater described above, can be employed. The walls of the reactor should be free of material which will catalyze the thermal dealkylation procedure defined herein, and the interior of the reactor should similarly be free of catalytic material. If desired the reactor can be filled with noncatalytic material, such as quartz chips, in order to effect better mixing and to reduce temperature gradients therein.
The temperature required to etfect the desired hydropressure is not critical and can be in excess of about pounds per square inch gauge, we prefer to employ apressure in the range of about 200 to about 1000 pounds per square inch gauge.
0.2, preferably about 0.5 to about 3.5 (total volume of monoalkylated phenol per free reactor volume per how) can be employed.
The reaction is continued and then terminated, as noted hereinabove, when no more than about 88 to 92 mol percent of the monoalkylated phenol has been converted. To terminate the reaction, the reaction mixture is quenched to a temperature where the reaction essentially ceases, which can be from about 80 to about 800 F., in any suitable manner, for example, by direct contact with cooled, previously-formed product.
Maximum selectivity of monoalkylated phenol to phenol has been obtained in the product so recovered. The product obtained consists essentially of phenol, monoalkylated benzene, such as toluene, benzene, unreacted monoalkylated phenol and hydrogen, methane, water and some heavy material believed to be conjugated phenol, toluene and benzene derivatives. To recover the phenol this product can be treated in any suitable manner to re move water therefrom, for example, by passing the same through 4A Linde molecular sieves or other adsorbent material having a greater specificity for water than the hydrocarbons or phenol. The remaining product for purposes of recovery can be separated into its individual components or selected combinations thereof by any suitable means, by fractional distillation at subatmospheric, atmospheric or superatmospheric pressure, for example, a temperature of about to about 450 F. and atmospheric pressure.
An extremely attractive feature of our present process is that While the process can be operated to obtain maximum selectivity to phenol, monoalkylated benzene produced can be further treated to produce additional benzene.
Thus from the reaction product a fraction thereof containing solely a monoalkylated benzene, such as toluene, or in combination with benzene, together with about one to about 10 mols thereof of hydrogen, can be subjected in the same reactor, or one similar to the reactor employed to convert monoalkylated phenol to phenol, to a temperature of about 1050 to about 1350 F. and a pressure of about 250 to about 1200 pounds per square inch gauge while employing a space velocity of about 0.5
to about 3.0. As a result thereof the monoalkylated ben- A space velocity of at least about zene, such as toluene, will be converted to benzene and methane will be obtained in the manner previously described. The product can be quenched to a temperature where the reaction essentially ceases, which can be in the range of about 80 to about 800 F., in any suitable manner, and the benzene recovered therefrom by fractional distillation at subatmospheric, atmospheric or superatmospheric pressures, for example, at 240 F. and atmospheric pressure.
The process of this invention can be further illustrated by reference to the following. Thermal hydrodealkylation runs were made, using as charge therefor ortho, metaand p-cresols, in a reactor having a length of four inches and an inner diameter of one inch filled with a noncatalytic material, quartz chips, to elfect better mixing and to reduce temperature gradients. Each of the charge stocks was mixed with hydrogen before preheating. The average reactor temperature was determined from several temperature measurements made inside the reactor with a movable chromel-alumel thermocouple. Pressures and temperatures were maintained at set values by means of automatic control instruments. The unit was run two hours offstream to allow for stabilization of process conditions.
The hydrogen employed in the thermal hydrodealkylation process defined herein need not be pure but may be present in a gaseous stream also containing materials which will not adversely affect the desired reaction. Coke oven gas, for example, can advantageously be employed for purposes of supplying hydrogen for the reaction. The composition of coke oven gas, in mol percent, is as follows: 53.1 percent hydrogen, 26.2 percent methane, 5.3 percent ethane and ethylene, 0.4 percent heavier hydrocarbons, 5.8 percent carbon monoxide, 2.8 percent carbon dioxide, 0.5 percent hydrogen sulphide and 5.9 percent nitrogen. Since the hydrogen in such stream is consumed in the process and a saturated aliphatic hydrocarbon, such as methane, is formed, the resultant gas will contain more saturated aliphatic hydrocarbon and less hydrogen than the charge gas. Since on a volume basis the saturated aliphatic hydrocarbon has a higher caloric value than hydrogen, the result-ant gas will have an enhanced caloric value. For such reason in some cases an impure hydrogen stream is desirable as a source of hydrogen.
Obviously many modifications and variations of the invention, as hereinabove set forth, can be made without departing from the spirit and scope thereof, and only such limitations should be imposed as are indicated in the appended claims.
We claim:
1. A process for converting a cresol which comprises Run N0 1 2 3 4 5 6 7 8 9 10 11 Charge. o-Cresol m-Cresol p-Cresol Duration of On-Strcam Period, Hrs 2 2 2 2 2 2 2 2 2 2 2 Conditions: 4
Temperature, F 1, 269 1, 355 1, 150 1, 250 1, 350 1, 153 1, 149 1, 266 1, 253 1, 250 1, 106 Pressure, p.s.i.g 775 775 775 775 750 750 75 750 750 750 Space Velocity, Vol./V0l./Hr 0. 97 0. 93 0. 80 1. 1 2. 0 1. 6 2. 1 2. 0 2. 6 0. 9 1. 9 Hydrogen/cresol, MoljMol- 3. 3 3. 2 4.0 4. 8 3.6 4. 8 4. 8 4. 8 4. 8 4.0 4. 8 Conversion, Mol Percent. 97. 7 96. 7 28. 7 76. 1 96. 1 39. 2 33. 3 73. 4 81. 4 94. 6 31. 6 Selectivity, Mo]. Percent:
Phen 21.1 1.6 85. 0 45. 6 18. 8 55.1 43. 6 49. 9 56. 2 48.0 52. 2 Bemene 63. 0 87. 7 l5. 0 28. l 62. 7 7. 0 4. 7 21. 4 16. 2 32. 5 3. 7 Toluene. 13. 4 0. 7 0. 0 17. 1 5. 9 35. 5 49. 3 18. 5 15. 1 14. 0 41. 4
Total Selectivity, Moi Percent 97. 5 90.0 100. 0 90. 8 87. 4 97. 6 97. 6 89.8 87. 5 94. 5 97. 3
The data from Table I are graphically represented in the drawing. With the exception of selectivity of meta cresol to phenol of 85 mol percent, which would be extremely desirable, at a conversion level of 28.7 mol percent, all of the data obtained fit to a single correlation reasonably well. The drawing shows that selectivity to phenol from cresol, particularly para cresol, was about 53 mol percent throughout the conversion range studied and that this selectivity was maintained until about 88 to about 92 mol percent of the cresol charge was converted. This constant selectivity provides evidence that phenol is produced by a primary decomposition of cresols and that it does not undergo secondary decomposition until conversion of any cresol is above about 8 8 to about 92 mol percent. Initially selectivity to toluene was high but low to benzene. With increasing conversion, however, selectivity to toluene greatly decreased, evidently because of secondary conversion to benzene. The evidence of a secondary decomposition of toluene is based on the fact that selectivity to benzene increased in proportion to toluene disappearance.
This result is an extremely attractive feature of our invention wherein cresol is converted to phenol and the remainder of the converted product is desired as benzene rather than toluene. Selectivity of cresol to phenol remains at its maximum throughout the reaction period. At the same time conversion of toluene to benzene is increased. At the end of the reaction period the toluene remaining can be recovered and dealkylated in the manner stated. In this way the cresol charge can be converted almost solely to phenol and benzene and to the maximum amounts of each, A
reacting a cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F., at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction product.
2. A process for converting ortho cresol which comprises reacting ortho cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction prodnot.
3. A process for converting meta cresol which comprises reacting rneta cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction product.
4. A process for converting para cresol which comprises reacting para cresol with at least about one mol per mol thereof of hydrogen at a temperature of about 900 to about 1600 F. at a space velocity of about 0.2 to about 3.5, terminating said reaction when about 88 to about 92 mol percent of said cresol has been converted and thereafter recovering phenol from the reaction product.
(References on following page) 5 6 References Cited by the Examiner Egloff: The Reactions of Pure Hydrocarbons (1937),
UNITED STATES PATENTS pages 530, 540, 541 p 1 947 64 2 1934 HUfmann et aL 2, 0i 621 X Gonikberg 6t 31.; Chem. Abstracts, 54322439-440 2,003,941 6/1935 Kahl 26O-621 X 960). 3,182,094 5/1965 Glazier et a1 260-672 5 FOREIGN PATENTS LEON ZITVER, Primary Examiner.
657,207 3/1938 Germany.
OTHER REFERENCES Ellis: Hydrogenation of Organic Substances (3nd edi- 10 D M, HELPER, Assistant Examiner 11011 1930), page 5 10.
HAROLD G. MOORE, Examiner.
Claims (2)
1. A PROCESS FOR CONVERTING A CRESOL WHICH COMPRISES REACTING A CRESOL WITH AT LEAST ABOUT ONE MOL PER MOL THEREOF OF HYDROGEN AT A TEMPERATURE OF ABOUT 900* TO ABOUT 1600* F., AT A SPACE VELOCITY OF ABOUT 0.2 TO ABOUT
3.5, TERMINATING SAID REACTION WHEN ABOUT 88 TO ABOUT 92 MOL PERCENT OF SAID CRESOL HAS BEEN CONVERTED AND THEREAFTER RECOVERING PHENOL FROM THE REACTION PRODUCT.
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| US245848A US3284513A (en) | 1962-12-19 | 1962-12-19 | Process for the thermal hydro-dealkylation of cresols |
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| US245848A US3284513A (en) | 1962-12-19 | 1962-12-19 | Process for the thermal hydro-dealkylation of cresols |
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| US3284513A true US3284513A (en) | 1966-11-08 |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4205017A (en) * | 1978-06-19 | 1980-05-27 | Phillips Petroleum Company | Hydrodehydroxylation process using a rhenium-fluorided alumina catalyst |
| US4225414A (en) * | 1979-02-26 | 1980-09-30 | The United States Of America As Represented By The United States Department Of Energy | Process for hydrocracking carbonaceous material to provide fuels or chemical feed stock |
| US4230895A (en) * | 1978-11-30 | 1980-10-28 | Hydrocarbon Research, Inc. | Thermal hydrodealkylation of alkyl phenols |
| US4331566A (en) * | 1978-05-04 | 1982-05-25 | Phillips Petroleum Company | Catalyst for hydrodealkylation process |
| JPS5888332A (en) * | 1981-11-09 | 1983-05-26 | ハイドロカ−ボン・リサ−チ・インコ−ポレ−テツド | Thermal hydrodealkylation of alkylated phenols |
| US4605790A (en) * | 1985-05-21 | 1986-08-12 | E. I. Du Pont De Nemours And Company | Phenol from coal and biomass |
| US11485694B2 (en) | 2019-02-04 | 2022-11-01 | China Petroleum & Chemical Corporation | Dealklylation and transalkylation of mixed phenols to make cresols |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1947648A (en) * | 1930-07-22 | 1934-02-20 | Firm Oberschlesischer Bergund | Process for the production of pure phenol cresols and benzol-hydrocarbons from crudetar phenols |
| US2003941A (en) * | 1933-05-10 | 1935-06-04 | Ruetgerswerke Ag | Process for the production of phenol |
| DE657207C (en) * | 1933-07-25 | 1938-03-01 | Gewerkschaft Mathias Stinnes | Process for the production of phenol from cresols |
| US3182094A (en) * | 1961-07-13 | 1965-05-04 | Gulf Research Development Co | Thermal hydrodealkylation process |
-
1962
- 1962-12-19 US US245848A patent/US3284513A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1947648A (en) * | 1930-07-22 | 1934-02-20 | Firm Oberschlesischer Bergund | Process for the production of pure phenol cresols and benzol-hydrocarbons from crudetar phenols |
| US2003941A (en) * | 1933-05-10 | 1935-06-04 | Ruetgerswerke Ag | Process for the production of phenol |
| DE657207C (en) * | 1933-07-25 | 1938-03-01 | Gewerkschaft Mathias Stinnes | Process for the production of phenol from cresols |
| US3182094A (en) * | 1961-07-13 | 1965-05-04 | Gulf Research Development Co | Thermal hydrodealkylation process |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4331566A (en) * | 1978-05-04 | 1982-05-25 | Phillips Petroleum Company | Catalyst for hydrodealkylation process |
| US4205017A (en) * | 1978-06-19 | 1980-05-27 | Phillips Petroleum Company | Hydrodehydroxylation process using a rhenium-fluorided alumina catalyst |
| US4230895A (en) * | 1978-11-30 | 1980-10-28 | Hydrocarbon Research, Inc. | Thermal hydrodealkylation of alkyl phenols |
| US4225414A (en) * | 1979-02-26 | 1980-09-30 | The United States Of America As Represented By The United States Department Of Energy | Process for hydrocracking carbonaceous material to provide fuels or chemical feed stock |
| JPS5888332A (en) * | 1981-11-09 | 1983-05-26 | ハイドロカ−ボン・リサ−チ・インコ−ポレ−テツド | Thermal hydrodealkylation of alkylated phenols |
| US4431850A (en) * | 1981-11-09 | 1984-02-14 | Hri, Inc. | Low temperature hydrodealkylation of alkylated phenols |
| US4605790A (en) * | 1985-05-21 | 1986-08-12 | E. I. Du Pont De Nemours And Company | Phenol from coal and biomass |
| US11485694B2 (en) | 2019-02-04 | 2022-11-01 | China Petroleum & Chemical Corporation | Dealklylation and transalkylation of mixed phenols to make cresols |
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